I would venture a guess that the 9 sec. differential is likely due to downforce. Even though the electric motors and battery could have been more powerful, I think the fact that the street car beats the race car at 0-60, is a testament to it's effectiveness...... We cannot rule out final drive ratio either. which could be higher on the race car? We could also assume that the higher weight of the street car could be a handicap on the track, but the effectiveness of the electric motors could zero out performance by adding the extra acceleration, turbo lag fill, and torque vectoring...... I would imagine just about any purpose built race car will be similarly faster than it's street car brethren.......